The influence of energy intake and percentage of body fat on the reproductive performance of nonpregnant mares.

Sixty mares in transition from winter anestrus to normal cyclicity were assigned to a 3 x 2 factorial experiment to determine the effect of energy intake and percentage of body fat on the interval to first ovulation. The factors were 1) percentage of body fat--thin (<11.5), good (11.5 to 15), or fat (>15); and 2) energy intake--maintenance (100% of National Research Council (NRC) digestible energy requirement for maintenance) or high energy (150% of NRC digestible energy requirement for maintenance). Percentage of body fat was estimated by ultrasonographic scanning of rump fat thickness. Energy treatments began on April 2 and ended on June 4. Mares were teased daily with a stallion and their ovaries were palpated per rectum daily or every third day. A high energy intake was effective in hastening ovulation for mares in the thin group (P < 0.05) but not for mares in the moderate or fat groups. Mares in the fat group had a shorter (P < 0.05) interval from April 2 to ovulation (26.4 +/- 4.2 d) than those in the good or high energy-thin groups (48.7 +/- 2.8 and 49.1 +/- 4.2 d, respectively). Duration of the initial estrus was shorter (P < 0.05) for mares in the fat group (16.2 +/- 5.7 d) compared with mares in the good group (34.7 +/- 3.9 d) and tended (P<0.12) to be shorter than mares in the high energy-thin group (29.0 +/- 5.7 d).

Splenomegaly in dogs. Predictors of neoplasia and survival after splenectomy.

Splenomegaly confirmed by surgery or necropsy in 100 dogs was diagnosed histologically as benign neoplasia (n = 1), primary splenic malignancy (n = 59), neoplastic metastases (n = 6), and nonneoplastic disease (n = 34). Dogs with known systemic disease, such as lymphoma and mast cell tumor, that caused splenomegaly were not included in the study. Hemangiosarcoma was the most common splenic disease (43 cases). Overall mean age of the dogs was 10.7 years, the most common breed was German Shepherd dog, and 72 of the dogs weighed more than 21 kg. Dogs with anemia, nucleated red blood cells, abnormal red blood cell morphology, or splenic rupture had a significantly greater chance of having splenic neoplasia (P less than 0.002). A multivariable logistic regression analysis found that the presence of anemia and splenic rupture in dogs with splenomegaly was up to 69% accurate in predicting presence of splenic neoplasia. After splenectomy, the median survival time of dogs with splenic neoplasia was 13 weeks. For dogs with nonneoplastic splenomegaly it was at least 36 weeks.

Evaluation of intra-articularly administered sodium monoiodoacetate-induced chemical injury to articular cartilage of horses.

Three doses of sodium monoiodoacetate (MIA) were used to induce degenerative changes in articular cartilage in middle carpal joints of horses. Twelve young (2- to 5-year-old) horses, free of lameness, were randomly allotted to 3 groups. One middle carpal joint of each horse was injected with 0.9% NaCl solution (control joint). The contralateral middle carpal joint was injected with 0.09 mg of MIA/kg of body weight (group 1); 0.12 mg/kg (group 2); or 0.16 mg/kg (group 3). After MIA administration, horses were allowed ad libitum exercise in a 2-acre paddock for 12 weeks. At the end of the study, gross and microscopic tissue changes were evaluated and biochemical analyses of articular cartilage were done. Grossly, diffuse partial-thickness articular cartilage lesions were observed in group-2 (n = 2) and group-3 (n = 4) horses, but not in group-1 horses. Articular cartilage uronic acid content was significantly (P less than 0.03) decreased in all MIA-injected joints, compared with controls. Articular cartilage matrix staining with safranin-O was decreased in 3 of 4 MIA-injected joints of group-1 horses and in all MIA-injected joints of group-2 and group-3 horses, compared with controls (P less than 0.06). Microscopic degenerative changes in articular cartilage were not significantly different between MIA-injected and control joints in group-1 horses, but were increased (P less than 0.06) in all MIA-injected joints of group-2 and group-3 horses, compared with controls. Qualitatively, decreased matrix staining and degenerative changes were more severe in group-3 horses. On the basis of articular cartilage gross and microscopic changes, as well as biochemical changes, 0.12 mg of MIA/kg injected intra-articularly was determined to induce moderate degrees of articular cartilage degeneration. This model of chemically induced articular cartilage injury could be useful for evaluating treatment effects of anti-arthritic drugs in horses.

Effect of sodium hyaluronate in collagenase-induced superficial digital flexor tendinitis in horses.

Superficial digital flexor tendinitis was induced in each forelimb of 8 horses by injecting 4,000 U of collagenase into the midmetacarpal region of the tendon. In each horse, each tendon was treated 24 and 96 hours after the collagenase injection with SC injections of sodium hyaluronate (treated limbs) or an equal volume of 0.9% NaCl solution (control limbs). Exercise was restricted for the first 3 weeks of the study, and a controlled exercise program was instituted for the remainder of the study. Horses were evaluated clinically for lameness, tendon swelling, and midmetacarpal limb circumference. Ultrasonographic examinations were performed regularly (11 examinations/horse) throughout the study, and all horses were euthanatized 12 weeks after collagenase injections. Tendons from 4 horses were harvested for biomechanical testing, and samples were obtained from tendons from the remaining 4 horses for biochemical analysis of collagen. Samples were obtained from all tendons for microscopic evaluation. Significant differences between treated and control tendons were not noticed in any of the variables examined in live horses, although trends toward less lameness in treated limbs and toward better healing on ultrasonographic examination in control limbs were recorded. Significant differences were not noticed in biomechanical or biochemical evaluations, and the only significant (P < 0.05) microscopic finding was more severe inflammation in tendons from treated limbs. This study did not reveal significant benefits of treatment with sodium hyaluronate outside a synovial sheath on tendon repair in collagenase-induced tendinitis.

Chronic flunixin meglumine therapy in foals.

Effects of a therapeutic dose of flunixin meglumine on gastric mucosa of horse foals were determined by endoscopy, double-contrast radiography, and gross and histologic examinations. Foals were administered 1.1 mg of flunixin meglumine/kg of body weight, PO/day for 30 days in an encapsulated form that was divided into 2 doses/day (group 1; n = 3) or by IM injection once a day (group 2; n = 7). Three control foals (group 3; n = 3) were administered capsules (n = 1) containing dextrose powder or IM injections (n = 2) of vehicle solution without flunixin meglumine. All 3 groups-1 foals given flunixin meglumine PO developed oral ulcers. Group-2 foals given flunixin meglumine IM did not develop oral ulcers. One control foal (group 3) developed 1 oral ulcer that healed during the study. Endoscopic examination revealed linear crease-like mucosal lesions in the glandular portion of the stomach in 2 group-2 foals. Radiographic evidence of gastric ulcers was observed in only 1 gastrogram of a group-1 foal. Foals were euthanatized, and necropsy revealed erosions and/or ulcers of the glandular portion of the stomach. Oral ulcers were observed in all 3 group-1 foals. Erosions of the glandular portion of the stomach developed in all 10 foals given flunixin meglumine, but did not develop in group-3 foals. Ulceration of the glandular portion of the stomach was present in 1 group-2 foal.

Effects of intra-articular administration of methylprednisolone acetate on normal equine articular cartilage.

The effects of the corticosteroid 6-alpha-methylprednisolone acetate on normal equine articular cartilage were evaluated, using the middle carpal joint in 4 clinically normal young horses. One middle carpal joint of each horse was injected 3 times with 100 mg of 6-alpha-methylprednisolone acetate, at 14-day intervals. The opposite middle carpal joint (control) was injected with 2.5 ml of lactated Ringer solution at the same intervals. Effects were studied until 8 weeks after the first injection. Evaluation included clinical and radiographic examination, and gross, microscopic, and biochemical evaluation of joint tissues. Horses remained clinically normal during the study, and significant radiographic changes were not observed. Safranin-0 matrix staining intensity and uronic acid content were significantly (P less than 0.05) lower and hydroxyproline content was significantly (P less than 0.05) higher in articular cartilage of corticosteroid-injected joints vs control joints.

Radiographic bone surveys in the evaluation of primary bone tumors in dogs.

Forty-two dogs with primary bone tumors underwent radiographic bone surveys. The use of radiographic bone surveys led to a higher yield in finding other nonclinically detectable neoplastic sites (7.1%) than did thoracic radiographs (4.7%). Multicentric bone tumors accounted for 9.5% of total cases. Bone infarcts were identified in 3 dogs (7.1%).

Ultrasonographic features of splenic lymphosarcoma in dogs: 12 cases (1980-1986).

The ultrasonographic appearance of the spleen and adjacent organs in 12 dogs with splenic lymphosarcoma was reviewed. Poorly marginated hypoechoic to anechoic nodules (4 mm to 3 cm in diameter) were found in all dogs. The anechoic nodules did not result in reflective shadowing or acoustic enhancement of the underlying tissues. The remainder of the splenic parenchyma appeared relatively hypoechoic when compared with the liver or renal cortices in 9 dogs. Recognition of this ultrasonographic pattern appears to be a useful diagnostic tool. Needle aspiration guided ultrasonographically will then enable histologic confirmation of lymphosarcoma.

Ultrasonographic diagnosis of portacaval shunts in young dogs.

Ultrasonography was performed on 21 young dogs with portacaval shunts. Initial ultrasonography revealed a small hypovascular liver in all dogs. Eight portacaval shunts (4 intrahepatic, 4 extrahepatic) were detected. Supplementary ultrasonography of dogs under general anesthesia and subjected to positive-pressure ventilation identified 6 additional intrahepatic portacaval shunts.

Ultrasonographic features of splenic hemangiosarcoma in dogs: 18 cases (1980-1986).

The medical records of 18 dogs in which ultrasonography was useful in making a diagnosis of splenic hemangiosarcoma were reviewed. Splenic ultrasonography revealed masses with echo patterns that ranged from anechoic fluid to hyperechoic tissue. In 7 dogs, metastasis was detected ultrasonographically as anechoic to hypoechoic lesions in the liver.

Comparison of radiography and ultrasonography in the evaluation of renal lesions in the dog.

Survey abdominal radiographs, excretory urograms, and nephrosonograms were obtained from 14 dogs with renal lesions. Renal enlargement was suspected on survey radiographs and confirmed by excretory urography in 13 dogs. Radiographic differentiation between a solid and cystic renal lesion was not possible in 9 dogs. Ultrasonography determined the presence of solid masses in 12 dogs, established the presence of a renal cyst in the opposite kidney in 1 dog, and revealed hydronephrosis in 2 dogs. Ultrasonography appeared to be more sensitive than radiography in differentiating the internal characteristics of renal lesions.

Cholecystography and cholecystoduodenostomy in the diagnosis and treatment of bile duct obstruction in a dog.

A common bile duct obstruction was documented in a dog, by performing cholecystography haparoscopic visualization facilitated performance of the cholecystography. Target cells were a consistent hematologic finding. Cholecystoduodenostomy, an easily performed surgical technique, allowed for restoration of bile flow and resolution of clinical signs.

Comparison of gonioscopy and ultrasound biomicroscopy for evaluating the iridocorneal angle in dogs.

OBJECTIVE: To compare iridocorneal angle grading systems on the basis of gonioscopy and ultrasound biomicroscopy (UBM). DESIGN: Original cross-sectional observational study. ANIMALS: 22 dogs. PROCEDURE: Gonioscopy, goniophotography, and UBM were performed on 38 eyes from dogs without clinical evidence of glaucoma in the eyes examined. RESULTS: Predominant gonioscopic grades derived from goniophotographs were considered normal (n = 26) and mild (12). Ultrasound biomicroscopy angle measurements ranged from 16 to 38 degrees (mean +/- SD, 26.2 +/- 4.5 degrees). Ciliary clefts depicted on UBM images were graded as open (n = 4), compact/narrow (23), and closed (11). Significant differences were not found between UBM-derived ciliary cleft grades and goniophotography-derived dysgenesis grades, nor between UBM-derived ciliary cleft grades and subjective gonioscopic grades. CLINICAL IMPLICATIONS: Because gonioscopy allows evaluation of the anterior face of the ciliary cleft, whereas UBM provides cross-sectional information of the iridocorneal filtration angle, UBM may yield more information regarding pathogenesis and prognosis of, and preferred management approaches to, glaucoma. Ultrasound biomicroscopy may also be useful as a predictor of glaucoma or to diagnose early stages of glaucoma.

Limb-sparing treatment for osteosarcoma in dogs.

Twenty dogs with spontaneously developing osteosarcoma of the extremities were treated with 1 of 3 multimodality limb-sparing procedures. Excision of the tumor was preceded by intra-arterial (IA) administration of cisplatin (cis-diamminedichloroplatinum) alone directed to the affected extremity, irradiation plus IA administration of cisplatin, or irradiation plus IV administration of cisplatin. All dogs were free of apparent metastatic disease at the time of initial treatment. After diagnosis, dogs administered cisplatin IA had selective angiography performed on arteries supplying the tumor, and 70 mg of cisplatin/m2 of body surface was administered over 2 hours. This protocol was repeated 3 weeks later. Dogs that were irradiated received 25 or 40 Gy in 10 fractions over a 22-day period. The first and last radiation doses were immediately preceded by IA administration of cisplatin. Dogs given IV treatment received 10 mg of cisplatin/m2 2 hours before each radiation fraction was administered. Three weeks after the last treatment, tumors were excised and the limb underwent orthopedic reconstruction, generally using cortical allografting and bone plating. Limb function, allograft healing, local tumor control, and metastatic dissemination were monitored. Limb function was good to excellent in 69% (11/16) of dogs evaluated. Forelimb-sparing procedures were generally associated with better function than were limb-sparing procedures performed on hind limbs. Local tumor control was obtained in 79% (11/14) of dogs thoroughly evaluated, with local recurrences in 3 dogs at 3, 4, and 7 months after treatment. Fifteen dogs developed metastatic disease at a median time of 8 months from the time of diagnosis. Mean and median survival times for all dogs, regardless of cause of death, were 11.7 and 8 months, respectively. Tumor necrosis greater than 80% was statistically associated with lack of recurrence. Of 16 dogs, 5 (31%) developed infections at the surgical site. Multimodality limb-sparing treatment is believed to be a viable alternative for appropriately selected dogs with osteosarcoma. The optimal method of treatment prior to or after tumor excision has not yet been established.

Monitoring the progression of renal failure in a horse with polycystic kidney disease: use of the reciprocal of serum creatinine concentration and sodium sulfanilate clearance half-time.

Sequential reciprocals of serum creatinine concentration and sodium sulfanilate clearance half-times were used to monitor a horse with chronic renal failure. The horse was diagnosed as having polycystic kidney disease; at least one cyst was of distal tubular origin. Using the plots of the sequential data, a reasonably accurate prediction was made for complete renal decompensation to develop.

Radiographic and ultrasonographic diagnosis of liver diseases in dogs and cats.

Various techniques utilized for the clinical investigation of small animal patients with signs of liver disease are discussed. The author reviews the evaluation of survey radiographs and selected radiographic contrast techniques, such as cholecystography. The author also outlines the basic principles of hepatic ultrasonography and includes examples of normal and abnormal hepatic ultrasonograms to demonstrate the application of this new imaging modality to the diagnosis of liver diseases.

Malignant versus nonmalignant bone disease.

Diagnosis of bone lesions other than fractures is difficult from radiographs alone because mixed patterns of lysis and bone proliferation are frequently observed. It is important to evaluate whether the lesion is single (monostotic) or involving multiple bones (polyostotic). Correlation of additional information such as the patient signalment, sex, geographic habitat, history, clinical findings, and prior therapy is useful to help establish the most accurate differential diagnosis. The presence of intramedullary lesions with expansile destructive pattern in the metaphyseal region of a middle-aged, large-breed dog is supportive for a diagnosis of a primary bone tumor or an aggressive mycotic osteomyelitis. Serial radiographic studies can be performed to evaluate progression. Rapid bone change tends to occur with neoplasia, whereas slower progression can occur with osteomyelitis. The location of change to the vertebrae, such as spondylitis and diskospondylitis, often helps in the understanding of the underlying disease process. Additional diagnostic procedures, such as biopsies with appropriate lesion sampling and evaluation of serum for fungal titers, should be considered to establish the diagnosis.

Ventricular septal defects in three familially-related female Saanen goats.

Ventricular septal defects were diagnosed in 3 familially-related Saanen goats, a 4-year-old doe and 2 female kids aged 18 weeks, by clinical examination, electrocardiography, phonocardiography and thoracic radiography. Findings were contrasted with those from 3 clinically normal goats. Cardiac catheterisation was attempted on the 2 affected kids before euthanasia. Blood pressure tracings and selective contrast cardioangiography successfully demonstrated the defect in one case, but the other died shortly after anaesthetic induction. The adult goat, suspected paternal grand-dam of the affected twins, died without premonitory signs at 4.5 years of age. Necropsy confirmed the diagnosis in all 3 cases.

Noninvasive monitoring of fetal growth and development in the Siberian polecat (Mustela eversmanni).

The Siberian polecat (Mustela eversmanni) is the preferred species to assess procedures and establish normative values for application in the related and endangered black-footed ferret (Mustela nigripes). This study was undertaken to physically, ultrasonographically, and radiographically evaluate fetal development in a spontaneously breeding captive Siberian polecat population. Ultrasonographically, fetal sac enlargement allowed presumptive pregnancy detection as early as 12 days of gestation, the fetal pole was the first definitive sign of pregnancy at about 18 days of gestation, when the fetal heart beat also appeared, and definitive pregnancy detection by ultrasound was essentially 100% accurate after 18 days. The estimation of fetal number by ultrasound was less reliable than by radiography, as it is in other litter-bearing species. Crown-rump growth, organ differentiation, and calcification patterns resembled those of domestic carnivores except that comparable developmental stages in polecats occurred at disproportionately later times, suggesting that young Siberian polecats are delivered in a less developed state. Careful palpation permitted detection of pregnancy after day 17 but with less certainty than with ultrasound. Radiographic evaluation was insensitive and of limited value for pregnancy detection until near term. Litter number and fetal detail were difficult to assess until ossification could be observed, 3-6 days before parturition.

Effects of FSH and LH on ovarian and follicular blood flow, follicular growth and oocyte developmental competence in young and old mares.

Objectives of the experiment were to determine the effects of mare age and gonadotropin treatments on dominant follicle vascularity, ovarian blood flow and dominant follicle growth and to associate follicular vascularity with oocyte developmental capacity. Growing follicles >30 mm from young (4-9 years) and old (>20 years) mares were assessed for blood flow using color Doppler ultrasonography before maturation induction with recombinant equine LH (eLH) and immediately prior to oocyte collection at 20-24 h after eLH. Pulsed Doppler was used to obtain resistance indices of ovarian arteries ipsilateral to preovulatory follicles. For eFSH-treated estrous cycles, eFSH administration was started after detection of a cohort of follicles ≥20 to <25 mm and continued until a follicle >30 mm. Oocytes were harvested using transvaginal, ultrasonic-guided aspirations and cultured and injected with sperm at 40 ± 1 h after eLH. Presumptive zygotes were incubated, and rates of cleavage (≥2 cells) and blastocyst formation were obtained. Embryos were transferred nonsurgically into recipients' uteri, and pregnancy rates were assessed. Vascularity (number of color pixels per total pixels) was higher (P=0.003) in the follicles of old compared to young mares, with no significant interaction of eFSH or eLH. Effects of eFSH and time from eLH on follicle vascularity were not significant. The vascularity of follicles associated with oocytes that did compared to those that did not form blastocysts was greater (P=0.048), although follicular vascularity was less (P=0.02) for follicles associated with oocytes that did compared to those that did not develop into pregnancies. Resistance indices were not different for age, eFSH treatment, time after eLH administration and oocyte developmental potential. Growth of the dominant follicle was not associated with vascularity, although advanced age tended (P=0.09) to have a negative effect on follicle growth.